Building Construction Illustrated - Past Paper PDF

FRANCIS D.K. CHING – BUILDING CONSTRUCTION ILLUSTRATED CHAPTER 1 – BUILDING SITE o 1987 United Nations World Commission on Environment and Development definition of “sustainable development”. o LEED for New Construction and Major Renovations o LEED for Existing Buildin...

FRANCIS D.K. CHING – BUILDING CONSTRUCTION ILLUSTRATED CHAPTER 1 – BUILDING SITE o 1987 United Nations World Commission on Environment and Development definition of “sustainable development”. o LEED for New Construction and Major Renovations o LEED for Existing Buildings: Operations and Maintenance o LEED for Commercial Interiors o LEED for Core and Shell o LEED for Schools o LEED for Retail o LEED for Healthcare o LEED for Homes o LEED for Neighborhood Development o Architecture 2030 o Greenhouse gases – carbon dioxide, methane and nitrous oxide o Soils – 2 broad classes based on physical composition and characteristics o Fine-grained soils – silt and clay o Soil profile – showing layers or strata called “horizons” and collected from test pit or boring. ▪ Standard Penetration Test – measures density of granular soils and the consistency of some clays at the bottom of a borehole, recording the number of blows required by a hammer to advance a standard soil sampler. ▪ Coarse-grained soils are more stable for foundation than silt or clay. Clay shrinks and swell. ▪ Shearing strength – ability to resist displacement when an external force is applied due to cohesion and internal friction. o Angle of Repose o Topography – configuration of surface features of a plot of land o Contour lines o Ground slopes: ▪ >10% - challenging for outdoor activities and expensive to build ▪ 5 – 10% - suitable for informal outdoor activities, not difficult ▪ 5% - usable for outdoor activities and relatively easy to build on o Decrease in temperature by altitude – 0.56 degC for every 122m of elevation o Plant Materials – many purposes such as wind breaks, screening views, sound attenuation, soil stabilizer, improve air quality, shading o Solar Radiation – altitude, azimuth, horizon, summer solstice, winter solstice o Solar constant – average rate of radiant energy from the sun ▪ South-facing glass or transparent plastic for solar collection ▪ Thermal mass – concrete (12-18”), brick (10”-14”, Adobe (8”-12”), Water (6”) o3 ways of passive solar heating ▪ direct gain (50-60% of total surface area), ▪ indirect gain (using thermal mass, Thrombe wall or drum wall) – other examples are sunspace (aka sunroom or solarium), roof pond ▪ isolated gain – collect and store solar radiation away from the space to be heated. o Solar shading o Horizontal overhangs – most effective in the southern orientations (can be horizontal louvers, slanter louvers) o Eggcrates – also brise-soleil, efficient in hot climates o Solar blinds – can reduce 50% in solar radiation o Precipitation – annual or seasonal rain or snow o Flat roofs – use scupper or interior roof drains o Site Drainage o Two types ▪ Subsurface drainage – underground pipes ▪ Surface drainage – by grading and surfacing o Curtain or interscepting drain – for protecting some area from groundwater source o Grade for drainage of finish grades – 5% minimum away from building o Slope of parking spaces – 2-3% o Swales – shallow depressions by intersecting two ground slopes. o Some elements of site drainage – dry wells, area drains, catch basins, culverts, catchment areas o Wind o Wind break – can be in the form of an earth berm, garden wall or a dense stand of trees. ▪ 2-5H is the windward shadow ▪ 10-15 is the leeward shadow o Sound and Views – expansive view, restrictive view, filtered view o Regulatory Factors o Pedestrian Circulation o 1.2m minimum for single bike path or lane o Vehicular Parking o Minimum overhead clearance – 2135mm o Slope Protection o Stabilization – to prevent erosion from the runoff of surface water ▪ Revetment of riprap or gabions – for embankments ▪ Cribbing (cellular walls) or bin walls (interlocking walls) – for steep embankments ▪ Soil binders – natural means of stabilization o Retaining wall – used when change in elevation exceeds the natural angle of repose, to resist the lateral pressure o Surcharge – additional load of the earth above o Failures of retaining walls – sliding, overturning or excessive settling o Reinforced Concrete Retaining Walls ▪ Gravity wall – uses the sheer weight and volume of its mass, for less than 3.00m ▪ T-type cantilevered wall – for up to 6.00m high ▪ Counterfort wall – used above 6.00m high, spaced at every ½ of wall height ▪ L-type cantilevered wall – for wall abutting a property line or any obstructions o Batter – backward slope of the face of the wall o Drainage of retaining walls ▪ Uses drainage mat with filter fabric or porous gravel backfill ▪ 2” weepholes @ 1.2 – 1.8m or perforated drainpipe o Retaining walls made from timber and concrete, brick or stone masonry ▪ Horizontal Timber Wall Deadman – timber, stone or stone mass buried in the ground as an anchor; used for walls over 900mm high and placed 1.8m interval ▪ Brick Veneer Wall ▪ Dry Stone Wall o Paving – wearing surface for pedestrian and vehicular traffic on a site, usually a composite structure, layers are pavement, base and subgrade; 1% minimum slope for drainage of paving o Two types of pavement: ▪ Flexible – unit pavers of concrete, stone or brick; requires edging to restrain horizontal movement; some can be permeable Unit pavers include brick paver, concrete unit paver, interlocking pavers grid or turf block, granite cobble, cut stone ▪ Rigid – RC slabs or paving units mortared over a concrete slab o Base – foundation of well-graded aggregate that transfers the pavement load to the subgrade, prevent upward migration of capillary water, can have a subbase of aggregates for heavy duty loads o Subgrade – ultimately carry the load, can be undisturbed soil or compacted soil o Paving patterns – running bond, stack bond, backetweave, octagon and dot, roman cobble, coursed ashlar, herringbone, turf block, random stone o Edging can be made of concrete footing, pressure-treated wood edge or curb o Site Plan – illustrates the existing natural and built features of a site and describes proposed construction in relation to these existing features o Site Description – legal description of a site consisting of the location and boundaries of a specific parcel of land o Metes and bounds – course and length of each boundary line o Survey plat – legal document describing the location, boundaries and dimensions of a tract or parcel of land o Rectangular system of survey – using grids, range, township (93.2 km2) containing 36 sections (1 square mile). CHAPTER 2 – THE BUILDING o Building systems – many systems in a building. These are the important physical systems in a building: o Structural System – involving superstructure (above foundation) and substructure (foundation). o Enclosure System – shell or envelope of a building such as roof, exterior walls, windows and doors. o Mechanical Systems – providing the essential services (i.e. water supply, sewage disposal systems, HVAC, electrical system, vertical transportation systems, fire-fighting systems, recycling systems etc). o The factors or considerations in the building systems are performance requirements, aesthetic qualities, regulatory constraints, economic considerations, environmental impact, construction practices o Building Codes – to regulate the design, construction, alteration and repair of buildings in order to protect the public safety, health and welfare o Model Codes o International Building Code o Companion Codes – i.e. International Residential Codes o Other Codes – i.e NFPA 70 (National Electrical Code), NFPA 101 (Life Safety Code), NFPA 13 (for fire sprinklers). o Federal Requirements ▪ Americans with Disabilities Act (ADA) of 1990 o Types of Construction – classification is based on structural frame, exterior and interior bearing walls, non- bearing walls and partitions, floor and roof assemblies. o Occupancy Classification – influences the degree of fire resistance, size of a building and nature of occupancy (i.e. number of occupants). o Occupancy separations – vertical or horizontal (slabs or walls) o Fire Separation Distance – setback STRUCTURAL SYSTEM o Loads on Buildings – two types of loads: o Static Loads – assumed to be applied slowly to a structure until the structural element fails or breaks (i.e. live loads which can be occupancy loads, snow loads, roof loads or rain loads, dead loads, ground pressure, water or hydraulic pressure on foundation, thermal stresses and impact loads). o Dynamic Loads – applied suddenly with rapid changes in magnitude and point of application: ▪ Wind load – forces by the kinetic energy of a moving mass of air usually horizontal which can cause sliding, uplift or overturning Wind pressures – assumed to be perpendicular to the building surfaces (can be positive pressure or negative/suction pressure) Design wind pressure – minimum design value for the building exterior surfaces measured at a height of 10m and using the critical wind velocity Flutter – rapid oscillations of cabled structures or flexible membrane due to aerodynamic effects of wind ▪ Earthquake load – series of longitudinal and tranverse vibrations induced in the earth’s crust by the abrupt movement of plates along fault lines Remember – the horizontal movements is more critical for structural design Base shear – minimum design value for the total lateral seismic force on a structure assumed to act in any horizontal direction; computed by multiplying the total dead load of the structure by a number of coefficients to reflect the character and  intensity of the ground motions in the seismic zone; can be computed for regular structures less than 73m high, low-rise irregular structures and structures at low-risk seismic areas For complex and irregular structures, wind dynamic analysis may be needed Natural period – varries according to height and dimension Overturning moment – generated by loads applied at high distance from the building base; this is counteracted by a restoring moment provided by the deadload of the structure; restoring moment is usually 50% of the overturning moment o Structural Forces – influences the shape or movemet of a body; vector quantity with magnitude and direction o Collinear forces – along a straight line o Concurrent forces – intersecting lines of action o Nonconcurrent forces – non-intersecting lines of action o Moment – tendency of a force to produce rotation of a body about a point or line o Couple – force system of two equal, parallel forces acting in opposite direction producing rotation in a body but not translation o Structural Equilibrium – state of balance or rest resulting from the equal action of opposing forces o Rigid body equilibrium – needs both translational equilibrium (all forces equal to zero) and rotational equilibrium (total moment is zero) o Concentrated load – acts on very small or particular point of a supporting structural element o Uniformly distributed load – loads with uniform magnitude over a length or area (i.e. live load on a floor deck or joist, or a wind load on a wall). o Free-body diagram – graphic representation of the complete system of applied and reactive forces in a body or isolated part of a body o Columns – rigid, slender structural members primarily supporting axial compressive loads at its ends o Short columns fail by crushing while long columns fail by buckling o Eccentric load can cause bending and uneven stress distribution o Kern area – in a column cross section where all compressive loads are concentrated (if compressive load applied outside this, tensile stresses will develop). o Buckling – sudden lateral or torsional instability of a slender structural member induced by the action of an axial load before the yield stress of the material is reached; higher slenderness ratio means more prone to buckling o Slenderness ratio – ratio of its effective length to its least radius of gyration ▪ Radius of gyration – distance of the mass concentration from the axis ▪ Effective length – distance between inflection points in a column ▪ Effective length factor (k) – applied to modify the actual length of column to determine its effective length 0.5 for fixed ends (smaller effective length means more load-carrying capacity) 0.7 for pinned and fixed ends 1.0 for both ends pinned 2.0 for one end free, one end fixed o Beams – rigid structural members designed to carry and transfer transverse loads across space to supporting elements o Deflection – perpendicular distance of a spanning member deviating from its true coarse o Bending moment – external moment causing structure to bend or rotate o Resisting moment – internal moment resisting yhe bending moment o Bending stress – combination of compressive and tensions stresses o Neutral axis – imaginary line along the centroid  o Transverse shear – occurs at the cross section of a beam o Vertical shearing stress – develops to resist transverse shear o Horizontal or longitudinal shearing stress – develops to prevent slippage along the horizontal planes of a beam o Beam efficiency depends on the configuration of the cross section to provide the required moment of inertia or section modulus with the smallest possible area ▪ Increasing the depth of beam section reduces the bending stresses more than ▪ Moment of inertia – the sum of the products of each element of an area and the square of its distance from a coplanar axis of rotation; geometric property of a structural member ▪ Section modulus – geometric property of a cross section, defined as the moment of inertia of the section divided by the distance from the neutral axis to the most remote surface o Beam types ▪ Simple beam – simple rests on support at both ends; no moment resistance at both ends; statically determinate structure ▪ Cantilever – projecting beam with only one fixed en ▪ Overhanging beam – simple beam extending beyond one of its support ▪ Double overhanging beam – simple beam extending beyong two of its support ▪ Fixed-end beam – both ends are fixed and with moment resistance; increased rigidity and reduces maximum deflection; indeterminate structure ▪ Suspended span – simble beam supported by overhangs of two adjoing spaces ▪ Continuous beam – extending over more than two supports o Trusses – structural frame based on the geometric rigidity of the triangle and composed of linear members subject only to axital tension or compression o Top and bottom chords – principal members extending from end to end o Web – integral system of members connecting the upper and lower chords o Panel – any of the spaces within the web of truss o Heel – lower supported end of a truss o Panel point – any of the joints between principal web member and a chord o Zero-force members – carry no direct load and can be ommitted o Vierendeel trusses – framed beam structures having vertical web members rigidly connected to parallel top and bottom chords; not true trusses because webs are not subject to axial bending forces o Frames and Walls o Rigid frame – assembly of columns and beams connected to resist both forces and moments; also statically indeterminate ▪ Fixed frame – rigid frame with fixed supports; more resistant to deflection but more prone to settlement and thermal expansion or contraction than hinge frame ▪ Hinged frame – rigid frame with pinned supports; prevents high bending stresses because it can rotate as a unit and to flex with thermal expansion or changes ▪ Three-hinged frame – structural assembly of two-rigid sections connected to each other and to its supports with pin joints; more sensitive to deflection than either the fixed or hinged frame and more resistant to settlements and thermal stresses o Load-bearing walls – most effective in carrying coplanar, uniformly distributed loads and most vulnerable to forces perpendicular to their planes; must rely to buttresses, crosswalls, tranverse rigid frames and horizontal slabs for lateral stability; can be weakened by the openings o Plate structures – rigid, planar, usually monolithic strurctures dispersing loads in multidirectional pattern (i.e. reinforced concrete slab); can be simplified as series of adjacent beam strips; can be one-way or two-way depending on the dimensions  ▪ Folded plate structures – thin, deep elements joined rigidly along their boundaries with sharp angles to brace and resist lateal buckling; acting as beams in longitudinal direction and continuous beam supported at fold points in the transverse direction; vertical diaphrams help stiffen the structure which can span relatively long distances o Space frame – composed of short rigid linear elements triangulated in three dimensions and subject only to axial tension or compression ▪ Tetrahedron – simplest spatial unit of a space frame having 4 joints and 6 members o Structural Units – basic building or spatial block of the structural system; basically an assembly of the structural elements like columns, beams, slab or wall to define a spatial volume o Example – column-and-beam frame, bearing wall, slab or plate structure, beams or girders, joists, planks or decking o Spanning systems – depend on the dimensions and proportions of a structural unit or bay ▪ One-way systems – can be of slabs, planks or joists (ratio if 1.5:1) Load-bearing walls are most effective when supporting a uniformly distributed load, they typically support a series of joists, planks or a one-way slab ▪ Two-way systems – can be of beams or slabs o Structural Spans – determine the spacing of vertical supports; span ranges are the following: o Timber – planks (2-5m), joists (2-5m), laminated beams (3-25m), trusses (6m and above) o Steel – decking (2-5m), wide flange beams (4-18m), open-web joists (4-28m) o Reinforced Concrete – one-way slabs (3-5m), joist slabs (4-11m), precast planks (3 -12m), precast tees (5m and above), Flat plates (4-7m), Two-way slabs & beams (4-12m), waffle slabs (8-16m) o Structural Patterns – arrangement of principal vertical supports and spanning systems (beams =, joists and girders). o Grid – defined by the principal points and lines of support; can be regular, irregular, parallel or offset o Lateral Stability – against lateral wind and seismic forces from any direction; involving shear walls, rigid or braced frame and horizontal diaphragm; in terms of lateral stability, the rigid frame is the least efficient; in rectangular buildings, lateral forces is more critical in the short direction o Types of bracing – knee bracing, K-brace, cross bracing, cable bracing o To avoid torsional effects, lateral force resisting elements are arrranged and braced symmetrically with centers of mass and resistance as coincident as possible because assymetrical layout or irregular structures will need more dynamic analysis (i.e. irregular structures are assymetric massing, soft or weak storey or a discontinuous shear wall or diaphragm). o Torsional irregularity – asymmetrical layout with center of mass and resistance not coincident (i.e. reentrant corners, discontinuous shear walls, soft or weak storey, discontinuous diaphragm). o Reentrant corner – plan configurations which is unstable during earthquakes because of high concentration of stress; can be relieved using seismic joints or gaps whch separates the components into simpler shapes o High-rise structures – very susceptible to lateral forces unlike lower structures o Generally, rigid frames are used for low-rise to mid-rise while high-rise needs diagonal bracing or rigid core. o Types of Structural Configurations for High-Rise: ▪ Framed Tube – closely spaced perimeter columns rigidly connected by deep spandrel beams ▪ Perforated shell tube – perimeter shear walls with less than 30% of the surface is perforated with openings ▪ Braced tube – framed structure tied together by a system of diagonal braces ▪ Trussed tube – with trussed wall frames of widely spaced columns tied together by diagonal or cross bracing.  ▪ Latticed truss tube – perimeter frames of closely spaced diagonals with no vertical columns. ▪ Bundled tubes – assembly of narrow tubes tied directly to each other to form a modular structure that behaves like a multicellular box girder cantilevered from the ground ▪ Tube-in-tube structure – with inner braced core added to the perimeter tube to improve its shear stiffness in resisting lateral forces o Damping mechanisms – viscoelastic mechanisms installed in structural joints to absorb wind or earthquake forces, can diminish vibratory or oscillatory motions and prevent destructive resonances ▪ Tuned mass damper – heavy mass mounted on rollers and attached to the upper portion of a tall building ▪ Base isolation – allowing the superstructure to float as a rigid body and alter the natural period of vibration of the structure ▪ Internal damping – damping caused by internal conditions like friction between structural elements or the molecules of structural members (hysterisis damping) or the viscuous resistance of fluid such as silicone oil (viscuous damping) o Arches and Vaults – other structural elements that can be used aside from the common elements like columns, beams, slabs and bearing walls o Arches – curved structures spanning an opening by supporting loads thru axial compression, transmitting them to abutments on either sides; thrusts coincide with the axis of the arch shape; ▪ Masonry arches – made of masonry units called voussoirs ▪ Rigid arches – curved rigid structures such as steel, timber or RC o Vaults – arched structures of stone, brick or reinforced concrete forming as a ceiling or roof, basically an extended arch ▪ Barrel vaults – semi-circular cross sections ▪ Groin or cross vaults – compound vaults of perpendicular intersection of two vaults which forms diagonal arrises called groins o Domes – spherical surface with circular plan and constructed of stacked blocks, basically a rotated arch; compressive near the crown and tensile near the lower; o Meridional forces – vertical direction downwards o Hoop forces – restraining out-of-plane movement of the meridional strips in the shell of a dome (can be compressive or tensile) o Tension ring – portion that a dome that contain the outward components of the meridional forces o Configurations of steel domes: ▪ Schwedler domes - horizontal circles, vertical and diagonal members ▪ Lattice dome – with horizontal circles and two diagonals ▪ Geodesic domes – with three principal sets of circles intersecting at 60 degrees o Shell Structures – thin curved plate structures usually of reinforced concrete; transmitting applied forces by membrane stresses of combined compressive, tensile and shear acting on the plane surfaces; suitable for uniformly distributed loads o Barrel shells – cylindrical shell structures which behaves as a deep beam if length is 3x the short dimension and as an arch is short o Hyperbolic paraboloids o Saddle surfaces – upward curvature in one direction (acting as arch) and downward curvature in another direction (acting as cable) o One-sheet hyperboloid o Surfaces can be translational (i.e. barrel shells and hyperbolic paraboloid), rotational (i.e. domes) and ruled surfaces (i.e. saddle surface or one-sheet hyperboloid)  o Cable Structures – utilize cable as the principal means of support; cables are in tensile and without compression or bending o Funicular shape o Catenary shape – freely suspended cable o Suspension structures – network of cables suspended and prestressed between compression members to directly support applied loads; can be single-curvature or double-curvature o Cable-stayed structures – with vertical of inclined masts where cables are extended supporting spaces in parallel or radial pattern o Guy cables and masts – components in cable structures o Membrane structures – thin, flexible surfaces carrying loads through tensile stresses; can be suspended, stretched or pneumatic (using air); o Pneumatic structures – membranes placed in tension using air; membranes can be woven textile or glass-fiber fabric coated synthetic materials such as silicone: ▪ Air-supported – single-membrane supported by internal pressure higher than the normal atmospheric pressure, anchored and sealed by airlocks ▪ Air-inflated structures – supported by pressurized air within inflated membranes (double membranes) o Joints and Connections – important for the transfer of forces; three common joints of structural are butt joints, overlapping joints and pinned joints. o Pinned joints – allow rotation not translation in any direction o Rigid or fixed joints – maintain the angular relationship between the joined elements, restrain rotation and translation in any direction, both have force and moment resistance o Roller joints – allow rotation but resist translation o Cable anchorage – allows rotation but resist translation only in the direction of the cable CHAPTER 3 – FOUNDATION SYSTEMS FOUNDATION SYSTEMS o Foundation – the lowest division of building (aka substructure); primary function is to support and anchor the superstructure above and transmit load to the earth; can involve basement walls or foundation walls, crawl spaces, slabs on grades, grid of piers or poles o Active earth pressure – exerted by soil mass on a basement wall o Passive earth pressure – in response to the horizontal movement of a foundation o Settlement – gradual subsiding of a structures as the soil consolidates under loading o Consolidation and settlement are quick and slight in granular soils such as sand and gravel while for moist or cohesive clay, it can be large and occurs slowly (not ideal as foundation). o Differential settlement – the relative movement of different parts of a structure due to uneven consolidation of the foundatio soil o Types of Foundation Systems o Shallow Foundations (also known as spread foundations) – used in stable soils of adequate bearing capacity near the ground o Deep Foundations – used for unstable soils with inadequate soil bearing capacity; rely on appropriate bearing stratum of rock or dense sands and gravel o Underpinning – rebuilding or strengthening the foundation of an existing building extending it when a new excavation in adjoining property is deeper than the existing foundation; methods include: o Needle beams o Intermittent pits under the existing foundation o Constructing piles or piers on either side the existing foundation o Excavation Support Systems – used when the excavation is too deep and bench terraced or sloped sides are not possible (or if angle is greater than the angle or repose) o Sheet Piling – consist of timber, steel or precast concrete planks driven vertically side by side which can be left in place as part of the substructure o Soldier piles or beams – steel H-section driven and supporting horizontal lagging o Other components: ▪ Lagging – heavy timber planks as the supporting face of an excavation ▪ Wales – horizontal supports of sheet piles or soldier piles ▪ Rakers or crossbracing – diagonal supports of sheet piles or solider piles ▪ Tiebacks – secured to rock or soil anchors (i.e. deadman), alternative to cross bracing or rakers; steel cables or tendonds inserted into predrilled holes and grouted under pressure o Slurry wall – concrete wall cast in a trench to serve as sheeting and often as permanent foundation wall; uses slurry of bentonite and water for the sides and reinforced concrete o Dewatering – process of lowering the watertable to prevent filling of water in the excavation; done by driving perforated tubes called well points o Shallow Foundations o Spread footings – lowest part of a shallow foundation; extended lateraly to distribute load over a wide area ▪ Concrete cover for the reinforcement – 3” (75mm) below, 6” (150mm) above ▪ For footings of light frame construction is on stable, noncohesive soil and transmit a continuous load of less than 2,000 lbs/f, crosssection can be: T = thickness of concrete wall (min. of 8” or 205mm) Footinf Projection = ½ T Thickess of footing = T Width of footing = 2T ▪ Frost line – depth where soil underground is frozen, usually 12” or 305mm ▪ Forms of spread footings Strip footings – continuous for foundation walls Isolated footings – individual footings for supporting freestanding columns and piers Continuous footing – extended footing to support multiple columns o Grade beam – RC beam supporting a bearing wall connected to footings, piers or piles Cantilever or strap footing – column footings with tie beams to balance a asymmetrically imposed load; used for foundation abutting property lines Combined footing – RC footing for a perimeter foundation wall or column extended to support an interior column load; used for foundation abutting property lines o Mat or raft foundation – thick, heavily reinforced concrete slab serving as a single monolithic footing for a number of columns; used when the bearing capacity of soil is to low that combining all footings for columns is more economical; can be stiffened by beams or grids ▪ Floating foundation – a special mat or raft foundation where the depth of the mat is placed deep enough that the weight of the excavated soil is equal or greater than the weight of the construction (so technicall the building floats or it replaced the excavated soil) o Foundation Walls – connected to the wall system or floor system o Some of the requirements: ▪ Extend foundation above finish grade – 6” or 150mm if supporting wood construction ▪ Finish grade slopes away from the foundation – 5% minimum ▪ Positive anchorage ▪ Consider dampproofing or waterproofing  ▪ Consider subsoil drainage system ▪ Expansion joints filled with promolded filler and sealant ▪ Crawl spaces – used for mechanical, electrical and plumbing installations With screen openings and located 6” or 150mm above the ground Clear height is about 450mm to 610mm o Types of Construction: ▪ Concrete Foundation Walls (cast-in-place) – requires formwork With anchor bolts for sill plates of light frame construction 8” or 205mm minimum wall thickness ▪ Concrete Masonry Walls – no required formwork 8” or 205mm minimum thickness o Connections/Anchorage to Upper Structures ▪ Sill plate anchors or holddowns – securing wall and floor framing to the foundation; involves anchor bolts embedded on concrete, sills etc. ▪ Typical sill plate is pressure-treated 2x6 or 2x8 ▪ For wood beams to concrete – 13mm minimum air space on tops, sides and ends; 75mm minimum bearing for wood beams supported on concrete ▪ For open-web steel joists to concrete – use steel base plates anchored to concrete; minimum bearing is 4”-6” for regular joists and 6”-9” for long span joists o Dampproofing and Waterproofing of Foundation Walls – dampproofing is enough for conditions where hydrostatic pressure from the groundtable will not occur, otherwise waterproofing is needed; ▪ Requirements: Dampproofing and waterproofing should extend 6” or 150mm above grade down to the top of the footing Dampproofing – can of bituminous or acrylic modified cement coating Waterproofing – can be of rubberized or polymer-modified asphalt, butyl rubber or other approved material capable of bridging nonstructural crack; bentonite clay can be used on joints or voids; protection needed when backfilling to avoid puncturing the waterproofing membrane Premolded filler and expansion joint; bentonite clay or waterstop can be used to seal or waterproof joints between slab and foundation wall o Subsoil Drainage Systems – for collecting and diverting water away from a foundation to a storm sewer, dry well or natural outfall at a lower elevation on the site ▪ Drainage mat or gravel backfill – allowing water to flow down to the footing drains; drainage mat approximately ¾” (19mm) thick made of synthetic matting or eggcrate core faced with a filter fabric that allows water to pass freely but prevents the passage of fine soil particles ▪ Perforated pipe or drain tile – 4” (100mm) minimum, pipe invert 2” (51mm) below elevation of slab, protect top with filter fabric, minimum 6” (150mm) cover of gravel or crushed stone o Treated Wood Foundation Systems ▪ Size of sump – 24” or 20” square, at least 24” (610mm) below the bottom of the slab ▪ Typical commerical size for sump pit insert – 18” diameter and 24” or 30” depth o Column Footings ▪ Structural considerations: Effective Depth Vertical and Lateral Reinforcement Critical Section for 1-way shear and 2-way shear Can be Wood, Reinforced Concrete or Steel Columns o Foundations on Sloping Ground  ▪ Distance of foundations from slopes >100% (angled more than 45 degress) and below finish – H/3 or 40’ (12m) maximum ▪ Distance of foundations from slopes >100% (angled more than 45 degrees) and above finish – H/2 or 15’ (5m) maximum ▪ Bearing prism on footings – 60deg for rock and 30deg for soil o Concrete Slabs on Grade – requires level, stable, uniformly dense or properly compacted soil base containing no organic matter o Typical Requirements ▪ Requires level, stable and uniformly dense or compacted soil ▪ 4” (100mm) – minimum thickness ▪ 6-mil or 0.15mm polyethylene moisture barrierw with 2” (51mm) layer of sand above to absorb excess water from concrete during curing o Joints in a Slab or Grade – for movements ▪ Isolation Joints or Expansion Joints – allow movement between slab and walls or columns ▪ Construction Joints – provide a place for construction to stop and the continue later on; can also serve as isolation joins or control joints depending on the connections ▪ Control Joints – creating lines of weaknesses for cracking; spaced 15’ to 20’ (4.5 to 6.1m); thickness is 1/8” or 3mm and depth is ¼ slab depth; filled with joint filler or premolded or metal strip; can also be incorporated in a keyed joint; o Connections ▪ Masonry Wall Connections ▪ Stud wall connections ▪ Thickened slab can be done to support an interior bearing partition or incorporate air ducts o Thickened Edge Slab or Integral Footing ▪ Used in warm or temperate climate areas where little or no ground frost occurs, it may be economical to thicken the edges of a concrete slab on grade to form integral footings for the exterior walls o Different systems can be integrated with the slab such as heating ducts, heating pipes or pipe penetrations o Slab steps – 4” or 100mm minimum thickness, with chamfer or radius edge nosing o Pole Foundations – elevate timber structures above the ground plane, minimize excavation and preserve the topography and drainage of the site o Embedment Length of Poles ▪ Steep slopes – 1.2 to 2.4m ▪ Flat slopes – 1.2 to 1.5m o Connections of Wood Poles and Horizontal Members ▪ Notching or Dapping ▪ Spiked Grid Connector ▪ Wood Gussets or Metal Connectors o Deep Foundations – extend down through unsuitable or unstable soil to transfer loads to appropriate bearing stratum o Two principal types are pile foundations and caisson foundations o Pile Foundation – system of end-bearing or friction piles, pile caps and tie beams ▪ Typical Requirements: Piles spaced 760mm to 1220mm Piles can be treated timber, steel H-sections, concrete-filled pipes or precast reinforced or prestressed concrete Piles are driven by pile drivers  Piles can be end-bearing or friction piles ▪ Types of Piles Timber Piles – logs usually driven as friction piles Composite piles – made of two materials (i.e. timber pile with concrete upper section) H-piles or steel H-sections – can be encased in concrete Pipe Piles Precast concrete piles Cast-in-place concrete piles o Cased piles o Uncased piles ▪ Pedestal piles – type of uncased pile with enlarged foot Micropiles – high-capacity, small diameter piles (5” to 12” or 125mm to 305mm), drilled and grouted in-place piles typically reinforced; used for urbanized areas with restricted access and for underpinning or emergency repairs; installed with minimal vibration and disturbance o Caisson Foundations – cast-in-place, plain or RC formed by boring with a large auger or excavating by a hand a shaft in the earth and filling with concrete (also referred to as drilled piles or piers). ▪ Typical Requirements Usually reinforced Boring is 760mm or larger Can have enlarged foot or bell or base ▪ Types Socketed caissons – drilled into stratum of solid rock Rock caissons – socketed caissons with steel H-section core and concrete CHAPTER 4 – FLOOR SYSTEMS o Floor systems – horizontal planes for supporting loads, transferring loads to beams or columns o Can be composed series of linear beams and joists overlaid with a plane of sheathing or decking o Deflection rather than bending is the critical controlling factor of designing floor systems o Consider also the mechanical and electrical lines underneath the floor system o Materials for Floor Systems – concrete (can be cast-in-place or precast), steel (can support concrete or other composite materials), wood o Concrete Beams – cast-in-place beams usually formed along with the slab they support o Typical Requirements ▪ Beam Depth – L/16 (rule of thumb), usually increments of 2” ▪ Beam Width – 1/3 – ½ of beam depth, increments of 2” or 3”, should be equal to or greater than width of supporting columns ▪ Concrete cover – 38mm minimum ▪ Rebar spacing – 25mm minimum ▪ Bevel or chamfer – 19mm o Components of Reinforcements ▪ Top bars – necessary near the column and slab connection (negative moment) ▪ Bottom bars – necessary near the midspan (positive moment) ▪ Web reinforcement – resisting diagonal tension, can be bent bars or stirrups Bent bars – bent at 30 degrees where the diagonal tension is largest Stirrups – U-shaped or closed-loop bars  Note that diagonal tension results from the principal stresses acting at an angle to the longitudinal axis of a beam ▪ Hooks – bends at the end of tension bars to develop an equivalent embedment length for anchorage; can be 90-, 135- or 180-degree bends o Concrete Slabs – plate structures that are reinforced to span either one or both directions of a structural bay o Typical Requirements: ▪ With tensile and temperature reinforcement ▪ Thickness rule of thumbs – L/30 for floor slabs and L/36 for roofs o One-way slab – uniformly thick, reinforced in one direction and cast integrally with parallel supporting beams ▪ Suitable for light to moderate loads over short spans of 6’ to 18’ (1.8 to 5.5m) o One-way joist slab or ribbed slab – cast integrally with a series of closely spaced joists which in turn supported by a parallel set of beams, designed as a series of T-beams; more suitable for longer span and heavier loads than one-way slabs; ▪ Typical requirements: Tensile rebars in the ribs, temperature rebars in the slab Thickness of slab – 3” to 4.5” (75mm to 115mm) Total depth of slab – L/24 Width of joists – 5” to 9” (125mm to 230mm) ▪ Uses metal or fiberglass pans/molds typically 20” or 30” width and 6” to 20” high; usually tapered for easy removal ▪ With distribution ribs (parallel to the main joists/ribs) which are used for bettwe load distribution and joists bands ▪ Suitable for light to medium live loads over spans of 15’ to 36’ (4m – 10m) o Two-way slab and beam – reinforced in two directions with supporting beams and columns on all sides (nearly square in size); used for medium spans and heavy loads or for high lateral resistance ▪ Typical Requirements Minimum depth – 4” or 100mm Slab depth rule of thumbs – L/180 ▪ Suitable for 15’ to 40’ (4.6m to 12m) spans ▪ Typically divided into 2 strips – column strip and middle strip o Two-way waffle slab – two-way waffle slab reinforced by ribs in two directions, suitable for heavier loads and longer span ▪ Typical requirements Slab depth – 75 to 115mm or L/24 Rib width – 5” or 6” ▪ No pans or domes around the column ▪ Suitable for 24’ to 54’ (7m to 16m) o Two-way flat plate – concrete slab of uniform thickness in two or more directions without beams or girders; simple forming, lower floor to floor heights and flexibility in column placement; used for apartment and hotel construction ▪ Typical Requirements Slab depth – 5” to 12” (125mm to 305mm) or L/33 ▪ Suitable for light to moderate loads and span of 12’ to 24’ (3.6m to 7m) ▪ Thickness depends on the shear at column locations (punching shear) o Two-way flat slab – flat plate but thickened at its column supports to increase its shear strength and moment capacity  ▪ Typical Requirements Slab depth – 6” to 12” (150mm to 305mm) or L/36 ▪ Can have drop panels with minimum projection of 0.25m x slab thickness and width of 0.33 of span ▪ Can have column capitals (also added to drop panels) ▪ Suitable for relatively heavy loads and spans of 20’ to 40’ (6m to 12m) o Pre-stressed concrete – pretensioning or posttensioning of steel tendons to resist the service load. o Tendons – can be wire cables, bundled strands or bars o Two basic types: ▪ Pre-tensioning – tensioned steel before concrete is cast ▪ Post-tensioning – concrete is cast before steel is tensioned o Load-balancing – uses draped tendons to reduce deflection o Concrete Formwork and Shoring o Slab sheathing – can be plywood, hardboard or boards o Shoring – temporary supports for the placed concrete slab ▪ Adjustable shores ▪ Single-post wood shores ▪ Double-post shores ▪ Horizonta shoring – for supporting the slab itself o Bracing of the shoring – required to stiffen the support o Some parts include knee brace, ledger, blocking, kicker o Other special types ▪ Flying forms – movable by cranes ▪ Lift-slab construction – for multi-story buildings, cast at ground and lifted by jacks o Precast Concrete Floor Systems – usually composed of precast slabs, beams and structural tees supported in frames; typically prestressed for better efficiency resulting in less depth, reduced weight and longer spans; factory-fabricated units with consistent strength quality, durability and finish without on-site formworks; not suitable for irregular buildings o Examples of Precast concrete units – solid flat slabs, hollow core slabs, single tees, double tees, rectangular beams, L-shaped beams, inverted tee beams, o Precast Concrete Connections ▪ Elements involved in the connections of precast slabs – bearing strips or pad, grouted key lock, steel angle welds o Structural Steel Framing – use structural steel girders, beams and columns to construct skeleton frames; usually fabricated off-site; coated with fire retardants; most efficient when beams and girders are in regular grid (rectangular bay units). o Connections – usually transitional elements such as angles, tees or plates ▪ Bearing plates – used to distribute the concentrated column loads o Types: ▪ One-way beam system Typical span of beams is 20’ to 32’ (6m to 10m), spaced 6’ to 15’ (1.8m to 4.5m) ▪ Two-wat beam system – utilizes long-spanning plate girders or trusses to carry the primary beam o Steel Beams ▪ Typical Sections S shape – classic I-beam W shape – more structurally efficient C shape  Structural Tubing ▪ Typical Requirements Beam Depth – span/20 Girders Depth – span/15 Width – 1/3 to ½ of depth ▪ Plate girders – built-up from plates welded or riveted together; involves cover plates, stiffener angles ▪ Box girder – built-up but with hollow ▪ Castellated beams – fabricated by dividing the web of wide flange sections in zigzag cut then welding both halves together ▪ Steel Beam Connections – governed by moment connections, sheat connections and semi-rigid connections Moment connections (rigid frame) – usually by means of plates welded or bolted to the beam flanges and supporting column o Typical elements – stiffener, backing bar, tab plate, Shear connections (simple frame) – resist only shear and can rotate under gravity loads; requires shear wall or diagonal bracings for lateral stability o Angles, stabilizing angle, seat angle, tab plate Semi-rigid connections (semi-rigid frame) – connections assume beam and girder connections posses a limited but known moment-resisting capacity o Welded connections, end-plates welded to supporting column o Open-web steel joists – lightweight shop-fabricated steel members with trussed web; permits passage of mechanical elements; suitable for rectangular bays and uniformly distributed loads ▪ Types – K series (uses single bent bar), LH and DLH series (uses heavier web and chord members and for longer span) ▪ Naming – Depth + Series + Chord Designation = 32LH10 ▪ Typical requirements 100mm to 300mm bearing length Depth – 200 to 760mm for K series, 450 to 1220 for LH series and 1320 to 1830 for DLH series Span – 4-18m for K series, 9-18m for LH series and up to 44m for DLH Maximum Span = 24x of joist depth Spacing – 600mm to 3000mm but 1.2m spacing is common for large buildings Bridging can be required for lateral stability – horizontal or diagonal bridging spaced from 3m to 6m ▪ Floor decking installed on top ▪ For openings, trimmer joists are used o Metal Decking – corrugated metal panels to increase stiffness and spanning capability; serving as a working platform during construction and as a formwork for a sitecast concrete slab; secured by puddle welds and shear studs; thickness is 64mm to 75mm but 51mm is the minimum; rule of thumb for overall depth is L/24; three major types are: ▪ Form decking – permanent formwork for a reinforced concrete slab until it can support itself; depending on the depth, it can span from 450mm to 3660mm ▪ Composite decking – serves as a tensile reinforcement for the concrete slab to which it is bonded with embossed rib patterns; thickness ranges from 1.2m to 4.5m ▪ Cellular decking – manufactured by welding a corrugated sheet to a flat steel sheet, forming a series of spaces or raceways for wiring and also as acoustic ceiling  o Light-guage Steel Joists – manufactured by cold-forming sheet or strip steel which are now lighter, more dimensionally stable and can span longer than wood counterparts ▪ Types of light-gauge steel joists – nestable joists, C-joists and Joist closure ▪ Typical details Nominal depths – 150mm, 200mm, 255mm, 305mm, 355mm; rule of thumb for depth is L/20 Flange width – 38m, 45mm, 51mm and 64mm Gauges – 14 to 22 Span depending on height: o 6” – 3.0m to 4.2m o 8” – 3.6m to 5.4m o 10” – 4.2m to 6.7m o 12” – 5.4 to 8.0m Bearing – 38mm minimum on ends, 75mm minimum at interior supports Spacing – 16”, 24” or 48” depending on the applied loads Strap bridging used for lateral displacement – 5’ to 8’ (1.5m to 2.4m) ▪ Pre-punching are common for passage of piping and reducing the weight ▪ Stiffener required where concentrated loads are present such as column connections or interior supports o Light Wood Framing o Wood Joists – part of wood light-frame construction; susceptible to fire and decay ▪ Typical details Spacing – 12”, 16” or 24” (305mm, 405mm or 610mm) Bearing – 38mm minimum on wood or metal and 75mm on concrete or masonry Span (depending on depth) – 6” (3m), 8” (2.4m to 3.6m), 10” (3m to 4.2m), 12” (3.6m to 5.4m) Joist depth rule of thumb – L/16 Joist deflection maximum – L/360 Bridging can be wood or metal cross bracing or full-depth blocking spaced at 2.4m intervals; required if the joist depth is 6x more the thickness Maximum openings for pipe – diameter is 1/3 joist depth and 2” from the edges Maximun notches on edges for piping also – 1/6th of joist depth maximum, not within the middle third span ▪ Connections or Components Sill plate anchors or holddowns Toenail sill plates Minimum air space on concrete connection – 13mm Metal Joist Hangers – see pictures Wood is susceptible to shrinkage perpendicular to its grain Wood scabs – small wood strips connecting wood elements Connections of joist to steel beam or wood beam is by providing a ledger (or metal joist hanger) underneath with 38mm minimum bearing or joists can be above the steel beams Header or trimmer Maximum projection of joists beyond support (cantilevered part) is 610mm, if longer must be engineered Headers longer than 3m shall be designed as beams o Wood Subflooring – structural material spanning across the floor joists serving as a working platform during construction and provides a base for the finish flooring; assembled with the joist to act as structural diaphragm ▪ Common materials – plywood, OSB, waferboard and particle board ▪ Span rating – stamp details with two numbers (32/16) which means rafter spacing if used as roofing underlayment or joist spacing if used as subflooring o Prefabricated or pre-engineered wood joists and trusses – increasingly used to replace dimension lumber in framing floors; generally lighter and more dimensionally stable than sawn lumber; can have higher depth and longer span; depth of truss joists is L/18 ▪ I-joists – commercial depth is 12” to 24” and span from 4.8m (for 10” depth) and 7.6m (for 16” depth) (some say 6-18m span) Connections – stiffener under bearing walls, 90mm minimum bearing Spacing – 12”, 16” or 24” (common is 16” or 400) ▪ Wood truss joists – different variations but can span up to 18m or 24m (can also have steel web members) Connections – can be top or bottom bearing o Wood beams ▪ Typical requirements: Depth of beam – L/15 Beam width – 1/3 to ½ of beam depth Deflection – L/360 ▪ Different types: Solid sawn – properties depend on the lumber species, structural grade, modulus of elasticity, allowable bending and shear stress values and minimum deflection; o Built-up beam – beams attached together o Spaced beam o Flitch beam – with bolts on the sides o Box beam – gluing to or more plywood or OSB to sawn to LVL flanges (LVL means laminated veneer lumber) Glue-laminated timber – laminating stress-grade lumber with adhesive under controlled conditions; higher allowable unit stress than dimension lumber; can span up to 24m; depth is L/20 and width is ¼ to 1/3 of beam depth Parallel strand lumber (PSL) – structural lumber product made by bonding long, narrow wood strands together under heat and pressure using a waterproof adhesive; known as “parallam”; Laminated veneer lumber (LVL) – structural lumber product made by bonding layers of wood veneer together under heat and pressure using a waterproof adhesive ▪ Wood beam supports Masonry or Concrete Wall Support – use clip angles or beam seat; bearing is 75mm minimum Foundation Wall Support – use sill plate with 75mm minimum bearing Girder Support – use beam hanger, supplemented with metal tension tie; or use clip angle above the girder Splicing – allowed at point of zero moment (1/4 to 1/3 of the span); can be done by steel splice connector or mortice splice Column to beam connections: o Exposed column cap – made of steel o Exposed T-strap – minimum of 150mm bearing in direction of beam span  o Continuous post – use split ring or through bolts; or use steel clip angles, strap tie and steel brackets; or use bearing blocks underneath and with metal strap tie o Spaced post – use through bolts or split-ring with blocking o Concealed connection – use steel plate in sawn kerf o Interlocking connection – use through-bolts or split-ring o Wood Plank and Beam Framing – most effective when supporting moderate, evenly distributed loads; can be considered as heavy timber construction if combined with noncombustible exterior walls; disadvantage is impact sound transmission ▪ Beam spacing for wood planks – typically 1.2 to 2.4m ▪ Wood strip flooring right angle to planking ▪ Flooring can be wood decking, 2-4-1 plywood (type of plywood for flooring with standard joist spacing) or stressed skin panels (plywood facings bonded with adhesives under heat and pressure to lumber stringers and cross bracings). o Wood Decking System ▪ Typical Details: Depth of decking – L/30 Deflection of decking – L/240 Span Range – 1.8m to 6m ▪ Types of Wood Decking – solid or laminated ▪ Types of Surface Patterns for Exposed Ceilings – V-groove, Channel groove, Plain or molded spline, Striated ▪ Types of Span – simple plan (supported at ends results in most deflection), double span (most efficient), continuous span (spannign over for or more supports) CHAPTER 5 – WALL SYSTEMS o Walls – vertical constructions of a building that enclose, separate and protect its interior spaces; can be load-bearing or not; if rigid enouch, considered as shear walls; o Wall Systems o Structural frames – can be concrete, steel or timber o Concrete and Masonry Bearing walls – non-combustible and relies on the mass to carry the loads o Metal and wood stud walls – with studs spaced at 16” or 24” (400mm or 600mm); can accommodate thermal insulatio, vapor retarders and mechanical distribution o Concrete columns o Typical Requirements: ▪ Vertical reinforcement – 1% min to 8% max of gross cross-sectional area; 16mm minimum diameter; min. of 4 bars (tied) and 6 (spiral) ▪ Inclined bars (for lapping) – slope of 1:6 ▪ 38mm minimum concrete cover ▪ Minimum sections: Rectangular – 200mm minimum width, 96 sq.in. minimum area Round columns – 250mm minimum diameter ▪ Lateral ties – minimum 10mm; max spacing is 48dbties, 16dbmain or least dimension of column; corner bend max 135o with 150mm minimum ▪ Spiral ties – minimum 10mm; max spacing is 1/6diameter or 75mm; min. spacing 1.5x the size of coarse aggregates; ends turned 1.5 for anchorage o Concrete Walls o Typical Requirements ▪ Anchorage to columns, slabs and intersecting walls with 10mm bar minimum and 300mm minimum length ▪ Minimum ratio of vertical reinforcement to gross concrete area – 0.0012 ▪ Minimum ration of horizontal reinforcement to gross concrete area – 0.0020 o Minimum wall thickness ▪ 150mm – bearing walls ▪ 100mm – non-load bearing walls ▪ 51mm – non-bearing walls not used as shear elements ▪ 150mm – plain (unreinforced) walls with a height-to-thickness ratio of less than 22 ▪ 200mm – minimum for basement, foundation, fire or party walls o Concrete walls usually rest on strip footings o Openings of door and window – min. of 16mm extenting 600mm beyond the corners of the opening; 51mm clearance o Concrete Formwork – for concrete columns and walls o Column Forms ▪ Fiber forms – smooth and spiral finish (i.e. sonotube) ▪ Wood formwork – reusable forms for square or rectangular columns o Wall Forms ▪ Elements involved – spreaders, form ties, plywood sheathing, wood studs (vertical), wood walers (horizontal), sill plate, bracing o Contact surfaces used parting compound of oil, wax or plastic for removal o Form ties – keeping the wall forms from spreading under fluid pressure ▪ Snap ties – with notches to remove the ends ▪ She-bolts – waler rods inserted through the form and threaded onto the ends of an inner rod o Chamfer strips – used to produce smooth, rounded or beveled edge on the outside corner of a concrete member o Rustication trips – to produce a groove o Concrete Surfacing o Exposed aggregates – produced by sandblasting, acid etching, scrubbing or chemicals; can be exposed fine aggregates or exposed coarse aggregates o Beton brut (raw concrete) – concrete left in its natural state after formwork is removed with texture, joints and fasteners of a board form ▪ Sandblasted plywood ▪ Board-and-batten pattern ▪ Ribbed texture formliner o Concrete treatments – can be painted or dyed, sandblasted, rubbed or ground smooth, bush- hammered or jack-hammered o Precast Concrete Walls – concrete wall panels cast and steam-cured in a plant off-site, transported to the construction site and set in place with cranes as rigid components; used for greater structural effeciency, reduced panel thickness and longer spans. o Typical Details ▪ Width – 2.4m typical for all types (but can be up to 3.6m) ▪ Types – solid panels, composite (with insulation) or ribbed panels o Precast Concrete Columns – typically used with precast beams to form a structural frame; sizes are 10” x 10” (250mm x 250mm), 12” x 12” (300mm x 300mm) or 16” x 16” (400mm x 400mm) o Typical Requirements  ▪ Minimum bearing length – L/180 of span for slab, 51mm minimum for slabs and 75mm minimum for beams and stemmed members ▪ o Typical Connections ▪ Corbel – with neoprene bearing strip, steel angle welded to plates; used for slab to concrete ▪ Panel Joints – use backer rod and sealant ▪ Column Splice – uses steel plates, splice bars and drypack with non-shrink grout ▪ Concrete Footing connection – uses shim pads and non-shrink grout and embedded anchor ▪ Column base – uses steel base plate, leveling nuts, anchor bolts (1” minimum) and drypack with non-shrink grout o Tilt-up Construction – wall panels cast on-site horizontally and tilt-up to their final position o Masonry Walls – consisting of modular building blocks bonded together with mortar to form walls that are durable, fire-resistant and structurally efficient in compression o Materials – bricks, concrete blocks, clay tile, structural glass block, and natural or cut stone o Types – solid walls, cavity walls or veneered walls o Reinforcement – can have reinforcement or none (plain masonry) o Typical Requirements ▪ Minimum thickness – 205mm (bearing, shear walls) and 150mm (reinforced bearing, solid masonry less than 2.7m) o Mortar ▪ Cement mortar – made by mixing portland cement, sand and water. ▪ Lime mortar – is a mixture of lime, sand and water; rarely used due to slow hardening rate and low compressive strength ▪ Cement-lime mortar – cement with added lime to increase plasticity and water retentivity ▪ Masonry cement – proprietary mix of portland cement and other ingredients, as hydrated lime, plasticizers, air-entraining agents and gypsum, requiring only the addition of sand and water to make cement mortar ▪ Types based on strength – Type M (2500psi), S (1800psi), N (750mm), O, K o Solid Masonry – made of solid or hollow masonry units filled with mortar; uses horizontal reinforcement like truss ties or ladder ties ▪ Wythes can be bonded by masonry headers or metal wall ties o Grouted Masonry – interior joints filled entirely with grout as the work progresses which consolidate the adjoining materials into a solid mass o Cavity Walls – constructed of a facing and a backing wythe of either solid or hollow masonry units, completely separated by a continuous air space and bonded with metal wall ties or horizontal joint reinforcement; advantage includes better thermal insulation and water protection (if weepholes and flashing provided). o Reinforced Masonry Walls ▪ Reinforced grouted masonry – with 75mm grout cover for the rebars o Reinforced Concrete Unit Masonry ▪ Typical Requirements for the horizontal reinforcement: At Top of parapet walls At structurally connected floors and roofs At top of foundations Horizontal rebar spaced 3m maximum Vertical rebar spaced 1.2m maximum o Masonry Columns o Typical Requirements ▪ Minimum size – 12” or 300mm o Masonry Arches o Different types are gothic, lancet, drop arch, roman arch, basket handle, tudor arch, jack arch, french arch o Rise of arch – minimum 1” per foot of span (1:12) o Masonry Lintels – 45o load triangle o 205mm minimum bearing beyond openings o Expansion and Control Joints o Movement Joints – spaced 30-38m along unbroken wall length: ▪ At changes in wall height or thickness ▪ At columns, pilasters and wall intersections ▪ Near corners ▪ On both sides of openings ▪ One one side of openings o Expansion Joints – continuous, unobstructed slots constructed to close slightly to accommodate the moisture expansion of bricks and stone masonry surfaces; should provide lateral stability across the joint and be sealed to prevent the passage of air and water (i.e. premolded compressible joint filler, waterstop) o Control Joints – constructed to open slightly to accommodate the shrinkage of a concrete masonry as it dries after construction o Masonry Wall Sections o All floors and roofs that provide lateral support must be anchored mininmum 1.8m. o Take into consideration the minimum bearing length or area. o Corbers as support for floors or roofs are permitted only is thickness is 12” and above. o Masonry Bonding o Terminologies – wythe, course, collar joint, bed joint, head joint, stretcher, header, rowlock, soldier o Mortar Joints – concave, V-joint, weathered struck, flush, raked o Bonds – running bond, common bond, stack bond, flemish, garden wall bond, english bond o Structural Clay Tile – hollow tile of fired clay having parallel cells or cores and used typically in constructing walls and partitions; with grades LB (load-bearing) and LBX (load-bearing and for weather). o Structural Facing Tile – structural clay tile with glazed surface and used for facing walls and partitions, especially in areas subject to heavy wear, moisture problems and strict sanitation requirements; with grades FTS (weather exposed with moderat absorption etc) and FTX (weather exposed with low absorption etc). o Glass Block – transluscent, hollow block of glass with clear, textured or patterned faces, made by fusing two halves together with a partial vacuum inside; used for nonload-bearing exterior and interior walls and framed windows. o Typical Details: ▪ Sizes – 6” x 6”, 8” x 8”, 12” x 12”, 4” x 8” ▪ Thickness – 4” (100mm standard), 3” (75mm thinner units). o Requirements ▪ Maximum height of unsupported glass block walls – 6m for exterior and interior standard units andand 3m for exterior thin units ▪ Curved walls with expansion joints at each change in direction ▪ Minimum radii – 1.2m for standard 4’ blocks, 1.8m for 8” blocks, and 2.4m for 12” blocks  o End Connections ▪ Use steel angles or steel channels with 25mm minimum lap ▪ Use expansion strip o Adobe Construction – adobe and rammed earth construction use unfired, stabilized earth as the primary building material; low-cost alternative construction systems; low tensile strength but with a compressive strength of 300 psi or more o Adobe bricks – sun-dried clay masonry, traditionally used in countries with little rainfall; uses soil with 15-25% moisture content ▪ Common size - 250mm x 350mm with thickness of 50mm to 100mm o Rammed construction (pise de terre) – stiff mixture of clay, silt, sand and water that is compressed and dried within forms as a wall construction. o Requirements – bond beams, anchors for windows and doors, minimum thickness is 200mm (nonbearing walls) o Stone Masonry – durable, weather-resistant materials; have irregular sizes and shapes and varying physical properties; o Requirements – non-staining cement and noncorrosive ties shall be used to prevent discoloration of the stones o Ashlar – squared building stone finely dressed on all faces to permit vety thin joints o Types or Configurations ▪ Random rubble ▪ Coursed rubble ▪ Square rubble ▪ Random ashlar ▪ Coursed ashlar ▪ Broken rangework ▪ Rustication o Coping – capping or covering of a wall (i.e. splayed copings, saddle copings, copestones, dripstone o Quion – exterior angle of a masonry wall or one of the stones or bricks forming such an angle, usually differentiated from adjoining surfaces by material, texture, color, size or projection. o Long-and-short work – arrangement of rectangular quoins or jambstones set alternately horizontally and vertically. o Stringcourse or belt course – horizontal masonry course flush with or projecting beyond the face of a building, often molded to mark a division in the wall o Structural Steel Framing – conventionally made of rot-rolled beams and columns, open-web joists and metal decking; typically uses nonbearing curtain walls o Requirements – fire-resistive coatings or fire-proofing o Steel columns – most common is a W-shape (wide flange); other shapes are round pipes, rectangular or square, welded plates, cruciform, or compound columns o Connections: ▪ Beam connections – welded or with angles etc. ▪ Column splices – butt plates (for change in size), backer plate (for different flang thickness) ▪ Column bases – uses steel base plate, non-shrink grout, anchor bolts, also stiffener if needed o Light-gauge Steel Studs – manufactured by cold-forming sheet or strip steel; lightweight, noncombustible and dampproof. o Typical Requirements: ▪ Vertical studs spacing – 12”, 16” or 24” (300, 400 or 600mm) ▪ Horizontal channep bracing spacing – 1m to 1.5m  ▪ Diagonal steel strap bracing – welded to studs and runners ▪ Maximum height – 90mm (3.50m), 150mm (6.1m) and 205mm (8.50m) o Types and Types ▪ Channel Studs – 25mm minimum thickness ▪ C-Studs – 32mm minimum thickness o Connections o Balloon Framing – utilizes stud that rise the full height of the frame from the sill plate to the roof plate, with joists nailed to the studs and supported by sills or by ribbons let into the studs; rarely used today o Platform Framing – studs only one story high, resting on the top plates of the storey below or on the sill plates of the foundation wall; o Typical Details ▪ 2x4 studs – max height 4.2m, spacing 16” or 400mm ▪ 2X6 studs – max height 6.1m, spacing 24” or 610mm o Wood Stud Framing o Typical elements – top plates, corner assemblies, sole plates, sill plates, header, cripples, trimmer studs, box beams, lintels o Stud Wall Sheathing – ▪ Typical requirements 1/8” (3mm) joint spacing ▪ Types of sheathing used – rated panel (plywood), gypsum, fiberboard, rigid foam plastic o Wood Columns – can be solid, built-up or spaced; o Factors affecting strength – lumber species, compressive strenth parallel to the grain and slenderness ratio of the column o Solid sawn columns – made of well-seasoned wood o Built-up columns – glue-laminated or mechanically fastened o Spaced columns – two or more members separated at their ends and middle points by blocking and joined at their ends by timber connectors and bolts o Wood Post-and-Beam Framing – uses a framework of vertical posts and horizontal beams to carry both floor and roof loads; used along with plank-and-beam systems, o Heavy Timber Construction – made of noncombustible, fire-resistive exterior walls and wood members that meet the minimum size requirements such as: ▪ Floor decking – minimum 3” (75mm) T&G or minimum 1” (25m) splined planks ▪ Roof decking – minimum 2” (51mm) T&G or splined planks ▪ Beams and girders – minimum 6” (150mm) thickness and 10” (255mm) nominal depth ▪ Columns – minimum 8x8 when supporting floors and 8x6 when supporting roof only o Typical Requirements ▪ Larger bolts are more efficient than more smaller ones; with spacing depending on parallel and perpendicular to the grain o Timber Connectors – alternative to bolts; used for transferring shear between the faces of two timber members, used with a single bolt that serves to restrain and clamp the assembly together; more efficient than bolts or lagscrews because of larger area of load distribution ▪ Split-ring connectors – metal ring inserted into corresponding grooves cut into the faces; with tongue-and-groove; diameter ranges from 64mm to 100mm ▪ Shear plates – round plate of malleable iron inserted into a corresponding groove, flush with the face of a timber, and held in place by a single bolt; used in back-to-back pairs to develop shear resistance in demountable wood-to-wood connections, or singly in a wood- to-metal connection  o Other Connections ▪ Column Supports for Beams – beam hanger, steel angle with web stiffener, bearing block bolted to column ▪ Column-Beam Connections ▪ Column Base Supports – through-bolts with countersunk heads and nuts; or anchor strap cast into concrete foundation wall or pier CHAPTER 6 – ROOF SYSTEMS o Roof system – primary sheltering element for the interior spaces of a building; used for shedding rainwater and snow and to control the passage of moisture vapor, infiltration of air and flow of heat and solar radiation o Roof Slopes o Flat Roofs – require continuous membrane roofing material; minimum recommended slope of 1:50, drainage can be interior drains or scupper drains; can be made of reinforced concrete, timber, trusses or joists. o Sloping Roofs – low-slope (up to 3:12) or medium-to-high slope (4:12 to 12:12); can be wood or steel timbers, trusses or rafters etc. o Reinforced Concrete Roof Slabs – formed and site cast like concrete floor systems; typicall covered with membrane roofing; can be in other forms like folded plates, domes and shell structures o Typical details – slab with smooth troweled finish to receive insulation and roofing, vapor retarder, insulation roofing membrane and wearing course o Edge details – can be parapet wall with metal reglet and cap flashing, can be cantilevered, can support curtain wall (spandrel beam) o Precast Concrete Roof Systems – similar to precast floor systems; o Connections to columns or wall – corbel with bearing strip, minimum bearing length of 51mm, etc. o Structural Steel Roof Framing – can be used for framing flat or sloped roofs o Steel Rigid Frames – consisting of two columns and a beam or girder that are rigidly connected at their joints; o Typical Details ▪ Span – 30’ to 120’ (9m to 36m) ▪ Purlins – can be C or Z, spacing from 1.2-1.5m ▪ Frame Spacing – 6.1 to 7.3 meters ▪ Crown Depth – L/40 ▪ Pitch – 1:12 to 4:12 ▪ Shoulder depth – L/25 ▪ Wall Height – 2.4m to 9.1m ▪ Base – 205 to 510mm o Steel Trusses – generally fabricated by welding or bolting structural angles and tees together to form the triangulated framework; usuallt require steel gusste plates o Typical Requirements ▪ Depth range for pitched trusses – L/4 to L/5 ▪ Depth range for bowstring trusses – L/6 to L/8 ▪ Span range – 7 to 36m o Truss Types ▪ Flat trusses – not as efficient as pitched or bowstring trusses ▪ Pratt trusses – vertical webs in compression, diagonal webs in tension ▪ Howe trusses – vertical webs in tensions, diagonal webs in compression ▪ Belgain trusses – have only inclined members.  ▪ Fink trusses – belgian trusses having subdiagonals to reduce the length of the compression web members toward the centerline of the span. ▪ Warren trusses – with inclined members forming equilateral triangles. ▪ Bowstring trusses – curved top chord meeting a straigth bottom chord at each end ▪ Raised-chord trusses – bottom chord raised above the level of the supports ▪ Crescent trusses – top and bottom chords curving upward from a common point at each side ▪ Scissors trusses have tension members extending from the foot of each top chord to an immediate point on the opposite top chord. o Space Frames – long-spanning three-dimensional plate structure based on the rigidity of the triangle and composed of linear elements subject only to axial tension or compression; simplest spatial unit is a tetrahedron with four joints and six structural members. o Types of grid – triangular grid, square grid, hexagonal grid o Members – can be structural steel pipe, tubing, channel, tees or W-shapes o Connections – welded, bolted or threaded connections o Typical Requirements ▪ The frame or bay should be square or nearly square to ensure that it acts as a two-way structure ▪ Support should always be at a panel point, can be on top or bottom chord, or increased bearing through cruciform or frame capital ▪ Camber – ¼” per foot ▪ Depth range – L/12 to L/20 ▪ Span – 6 to 36 modules, 9-24m for column-supported frames, 9-39m for wall-supported frames ▪ Overhand – 15-30% of the span o Open-web Steel Joists – roofing system is similar in layout and construction to steel joist floor systems o Typical Requirements ▪ Horizontal or diagonal bridging is required, spaced from 3m to 6m depending on joist span and chord size ▪ Connections can be on parapet wall, bearing wall, end wall etc o Metal Roof Decking – corrugated to increse its stiffness and ability to span across open-web steel joists or more widely spaced; commonly used without a concrete topping but structural wood, cementitious panels or rigid foam insulation panels to bridge gaps; has low vapor permanence but because of the many discontinuities between the panels, it is not airtight. o Connections – panels are puddle-welded or mechanically fastened to the supporting steel joists or beams o Types – ribbed roof decking or cellular roof decking o Cementitious Roof Planks – manufactured with Portland cement, lightweight aggregate, an aerating compound and galvanized welded wire fabric enforcement. o Typical size – 400-600mm width, 2.7-3.6m long, thickness o Can have T&G edges, thickened edges for channel slabs o Another variations is roof planks made from wood fibers o Rafter Framing – can be made of wood, light-gauge frames etc. o Roofing Terminologies – ridge, dormers, gable, shed, eave, soffit, hip, valley ▪ Ridge board – nonstructural horizontal member where upper ends of rafter are aligned and fastened ▪ Ridge beam – structural horizontal member supporting the ends of rafters at the ridge of a roof  ▪ Common rafters – extending from a wall plate to a ridge board or ridge beam and support the sheathing and covering of a roof ▪ Hip rafters or valley rafters ▪ Collar ties – unites to opposing rafters below the ridge (usually upper third of rafter) ▪ Ties – resist outward thrusts of the rafters, can be designed as ceiling joists ▪ Knee wall – short walls supporting rafters at some intermediate position along their length ▪ Jack rafter – any rafter that is shorter than the full length of the roof slope, as one meeting a hip or a valley; can be jack hip rafter or valley hip rafter ▪ Dormer – can be gable dormer or shed dormer ▪ Barge or fly rafters – end rafters in the part of a gable roof that projects beyond the gable wall o Shapes of Roofs ▪ Gable Roof – slopes downward in two parts from the central ridge ▪ Hip Roof – have sloping ends and sides meeting an inclined projecting angle ▪ Gambrel Roof – divided on each side into a shallower slope above a steeper one ▪ Flat Roof – framed similarly to floor joist framing o Light-gauge Roof Framing – connected by screws or welded together ▪ Connections – angle clip, anchor clip, ▪ Typical rafter spacing – 300mm, 400mm, 600mm o Wood Rafter Framing ▪ Typical spacing of rafters – 300mm, 400mm, 600mm ▪ Rafter span – 3.0m to 6.7m (depending on depth 6” to 12”) ▪ Other requirements Ventilation at the peak or ridge is optional Steel anchor straps may be required Take note of elements like bardgeboard, frieze board ▪ Fascia – broad flat surface of the outer edge of the roof o Roof Sheathing – typically APA-rated plywood or wood panels; enhance the stiffness of rafters and as a base for various roofing materials o Wood Plank-and-Beam Framing – basically same as plank-and-beam floor systems; can be made of (1) roof beams and decking or (2) roof beams, purlins and decking. o Connections – can be angles, straps or bolts o Wood Trusses – spaced up to 2.4m depending on the spanning capability of the roof decking or planking o Span Range – 12 to 45m for shaped trusses, 12-33m for flat trusses o Depth Range – L/2 to L/6 for shaped trusses, L/10 to L/15 for flat trusses CHAPTER 7 – MOISTURE AND THERMAL PROTECTION o Underlayment – protects the roof sheathing from moisture until the roof shingles are applied o Typical requirements – 50mm top lap, 100mm side lap o Materials for underlayment – asphalt-saturated felt o Roofing Shingles – made of individual overlapping elements which are typically flat and rectangular in shape. o Wood Shingles – typically sawn from red cedar, white cedar, redwood and red cypress; o Wood Shakes – typically formed by splitting a short log into a number of tapered radial sections, resulting in at least one textured face; normally clear of hardwood; length ranges from 450mm and 610mm ▪ Types – tapersplit, handsplit, straightsplit  o Composition Shingles – have either inorganic fiberglass base or an organic felt base surfaced on the weather side with colored mineral; usually with self-healing adhesive or locking tabs for wind resistance o Slate Shingles – made of slate which is extremely durable, fire-resistant and low-maintenance roofing material; can be split, trimmed or drilled to receive copper nails or wire ties; typically heavier than normal roofing materials ▪ Slating methods or configuration – diagonal slating, honeycomb slating or open/spaced slating o Tile Roofing – consisting of clay or concrete units that overlap or interlock to create a strong textural pattern; also fire-resistant, durable and require little maintenance; also heavier and may require stronger roof framing o Typical Elements – ridge tiles, arris tiles, field tiles (for majority), hips, rakes and eaves tiles o Styles of Tiles – Mission or Spanish (convex and concave), Pantile (S-shaped section), Interlocking (flat and rectangular with grooves for connection), Shingle tiles (flat and rectangular overlapped) o Vegetated Roofing (green roofing) – consisting of vegetation planted in engineered soil or growing medium over a waterproof membrane; greater initial investment but protects the waterproofing from wear and tear and UV radiation; reduces heat island effect o Types – intensive (300mm minimum depth for larger plants or trees), extensive (low maintenance and lightweight with typically 100mm to 150mm depth) and modular (uses anodized aluminum containers or plastic trays with 75-100mm depth of soil for low-growing plant species). o Corrugated Metal Roofing – can be corrugated or ribbed type of roofing panels made of aluminum, galvanized steel, fiberglass or reinforced plastic or corrugated structural glass; usually with closure strips for sealing the seams o Minimum recommended slope – 3:12 o Purlin spacing – 600mm to 1800mm o Typical elements – hip flashing, ridge flashing, mechanical fastenings, o Sheet Metal Roofing – characterized by a strong visual pattern of interlocking seams and articulated ridges and roof edges; o Minimum recommended slope – 3:12 o Types of Seams – standing seams, batten seams, lock seams, roll seams, other fabricated seams o Flat Roof Assemblies – typically made of the following layers from the top: ▪ Wear course – can be roofing aggregate, ballast aggregate or plaza deck pavers ▪ Drainage layer – permits flow to the roof drains; can be aggregates, ballast layer, or drainage fabric ▪ Roofing membrane – waterproofing layer of the roof; minimum slope of 1:50 to drain water; two major types are built-up and single-ply Can be plysheets of fiberglass, asphalt-saturated felt or coal tar-saturated felt placed with hot steep asphalt or coal tar bitumen ▪ Thermal Insulation – can be installed in three positions (below the roof deck, between the roof deck and the roofing membrane or above the roofing membrane) Materials that can be used are batt insulation, rigid insulation such as concrete fill or rigid foam, ▪ Vapor retarder – impedes passage of water vapor; usually built-up material of low permeance and placed predominantly on the warm side of an assembly ▪ Roof deck – must be stiff enough to carry the expected load; decks can be steel deck (GA 22), wood (25mm minimum), plywood, structural wood-fiber deck, cast-in-place concrete, precast concrete, lightweight insulating concrete etc.  o Single-ply membrane roofing – applied by sheet form or liquid (if complex or with domes) ▪ Liquid-applied membranes – can be made of silicone, neoprene, butyl rubber and polyurethane ▪ Sheet membranes – can be thermoplastic membranes, PVC, polymer-modified bitumens, thermosetting membranes, EPDM (ethylene propylene diene monomer), CSPE (chlorosulfonated polyethylene) or Neoprene (polychloroprene) ▪ Thickness ranges from 0.8mm to 2.5mm, flexible and strong; characteristics vary on flame resistance, abrasion and degradation from UV, pollutants, oils and chemicals. ▪ Typical Installation Elements – metal cap for parapet wall, splicing sealant and lap cement, mechanical fasteners penetrating to roof deck, minimum 75mm lap splice ▪ EPDM Roofing – with three generatic systems: Fully Adhered System – using bonding adhesive fully adhered to concrete or roof deck; no slope limitation and used for complex roof forms Mechanically Fastened System – uses mechanical fasteners in splices; maximu slope is 18:12 Loose Laid, Ballasted System – both insulation and the membrane are laid loosely above the roof deck o Roof Drainage – system design depends on the area and intensity of rainfall o Installation Elements – scuppers or overfloow drains, gutters along the eaves, strainers for gutter openings, splash blocks o Slope roof – minimum of 1:50 o Downspout Requirements – 1 sq.in. per 100 ft2 of roof area; 75mm minimum diameter o Roof Flashing – ref